Inscrição na biblioteca: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Numerical Simulation on Bubble Growth Process and Heat Transfer Characteristics with Microlayer Evaporation in Nucleate Boiling for Water

Get access (open in a dialog) DOI: 10.1615/IHTC15.pbl.008911
pages 6045-6058

Resumo

Previous experimental measurements showed that a microlayer formed beneath a growing bubble during nucleate pool boiling. The initial microlayer thickness was of micrometer order and increased linearly with distance from the bubble inception site. Although the distribution and evaporation characteristics of the microlayer have been studied experimentally, the quantitative contribution of the microlayer evaporation was still not elucidated sufficiently. To clarify the heat transfer characteristics, especially the contribution of microlayer evaporation, numerical simulations are conducted using the volume of fluid method for two-phase flow induced by the growth of a single bubble in saturated nucleate pool boiling. A special model is proposed in this study to combine the microlayer and bulk liquid regions, the scales of which are extremely different. In this special model, the microlayer was neglected in the volume fraction calculation, whereas the evaporation from the microlayer was included by applying the source terms of the basic equations as a virtual microlayer. The tendencies of the calculated variations in the microlayer and bubble radii were similar to those of the earlier experimental results. The microlayer evaporation contributed approximately 40% to the total bubble volume, which is in overall agreement with the previous results.